A NASA satellite image from September 16, 2007 and released on September 21, 2007, shows Arctic summer sea ice. Reuters/NASA/Handout

In an out-of-the-ordinary move, Gavin Schmidt, director of NASA's Goddard Institute for Space Studies, has personally dismissed the claims of One Nation Senator Malcolm Roberts, who stated that the agency had falsified climate data in order to exaggerate the current status of global warming in the Arctic.

“You appear to hold a number of misconceptions which I am happy to clarify at this time,” wrote Dr. Schmidt in e-mails and letters to Senator Roberts, adding, “The claim that GISS has 'removed the 1940s warmth' in the Arctic is not correct.” The letter, dated Nov. 18, was obtained by Fairfax Media.

Schmidt further stated that the data is available on the agency’s website and can be freely used by anyone for analysis. “We are certainly gratified by the attention Australia pays to our analysis, but in case you have remaining questions, I urge you to perform your own analyses,” he wrote.

However, Schmidt said that NASA undertook a process wherein alteration of temperature figures is made. He explained in the letter as to why this step was required and wrote, “Homogenisation of the raw temperature records is a necessary task to ensure that non-climatic influences in the analysis are minimised as much as possible.

These adjustments (for station moves, instrumentation changes, urban heat island effects etc.) are estimated via comparisons with neighboring stations and using relevant metadata. If we were not to adjust for these effects, we would be rightly criticized for using uncorrected data,” he added.

Apparently, the conspiracy theory that NASA tampered with the climate date from 1940s has become the favourite conjecture of global warming skeptics for arguing that temperature rise at the North Pole isn't exceptional and hence, it is not necessary to take any action in the same concern.

Senator Roberts had written a letter to NASA on Nov. 14, saying that the agency “influenced” the data on global warming. Stating examples in his letter, Senator Roberts had asked Schmidt to clarify the “adjustments” made to the Arctic historical temperatures records, which NASA has responded to lately.

Acknowledging that he has received the letter, Senator Roberts recently stated on Twitter that he has not yet replied to it. He wrote in the tweet, "had not had a chance to reply as the email only arrived Saturday."